1. Field of the Invention
The present invention relates to compositions and methods useful for waterproofing or dampproofing various water-penetrable materials used in building construction and other civil engineering projects. The invented compositions are aqueous compositions including polymer latices useful as waterproofing agent pretreatments. The invented methods use these new aqueous pretreatment compositions as a component in a system to reduce water penetration through construction materials. The invention also includes packages including waterproofing agents and these new pretreatment compositions and structures to which these new pretreatment compositions and a waterproofing agent have been applied.
2. Description of Related Art
Various materials used in building construction and other civil engineering projects such as roads and bridges are susceptible to water penetration resulting either from their inherent properties or imperfections such as cracks or pores. Reducing or eliminating water penetration through structures formed of these materials often is desirable such as for below-grade building walls, and may be critical in certain structures such as those housing expensive electrical equipment or tunnels moving vehicular or pedestrian traffic under bodies of water. Available waterproofing agents include ethylene propylene diene monomer (EPDM) sheets, polyvinyl chloride sheets, Bentonite panels, built-up asphalt systems, coal tar-based, and other asphalt-based compositions. Asphalt-based compositions are preferred; most preferred are preformed, flexible sheet-like laminates of support film(s) and bituminous layer(s) (waterproofing laminates) such as described in U.S. Pat. Nos. 3,741,856; 3,853,682; and 3,900,102. Bituthene.RTM. brand of waterproofing membrane is an example of preferred, commercially available asphalt-based waterproofing agents.
Many currently available waterproofing agents are very effective when applied correctly. For example, when using waterproofing laminates as a waterproofing agent on structures contaminated by dirt, dust, or efflorescence current practice requires that a pretreatment be applied to the structure before application of the waterproofing laminate. Most pretreatments commercially available are based upon volatile organic compounds and usually contain high levels of these compounds as solvents. Known aqueous pretreatments, such as asphalt emulsions, have not been used widely because of poor water immersion resistance and freeze/thaw resistance. Consequently, use of most commercially available pretreatments is fraught with disadvantages including the need to exercise great care to avoid fire hazard and atmospheric release of volatile organic compounds, or risk of failure resulting from poor water immersion resistance or poor low temperature applicability.
Therefore, despite use of waterproofing agents that require pretreatment, such as waterproofing laminates, for many years, there has been and remains a need for pretreatment compositions which eliminate use of volatile organic compounds without sacrificing the strength and duration of the bond between the waterproofing agent and structure and which can be applied when ambient temperatures are significantly below the freezing point of water.
Acrylic latex formulations including about 27 wt. % latex solids and about 9 wt. % 2-butoxyethanol, about 4 wt. % 2-(2-ethoxyethoxy) ethanol, and about 1 wt. % dibutyl phthalate are known for use as lacquers. These formulations may have freezing points at or below 32.degree. F. but are not useful as waterproofing agent pretreatments at or below 25.degree. F.
U.S. Pat. No. 4,897,313 describes use of water-based acrylic latex compositions as waterproofing agent pretreatments. These pretreatment compositions overcome many of the disadvantages of other known aqueous pretreatments but cannot be used at temperatures at or below 25.degree. F.
Schmidt U.S. Pat. No. 3,940,540 teaches built-up roofing employing precoated felts inhibited from slipping by use of bituminous emulsions to bind the felts. A minor amount of compatible latex is incorporated into the emulsion to increase the adhesion of bonded felts.
Rosenberg et al. U.S. Pat. No. 4,172,830 is one of many examples of references disclosing sheet-like flexible materials used for waterproofing.
Uffner et al. U.S. Pat. No. 4,362,586 describes use of polyamide resins as primers for highway repairs using asphaltic membranes.
U.S. Pat. No. 4,731,399 discloses extending certain latices by addition of up to about 40% by weight of an emulsion of asphalt, bitumen, or coal tar. The extended latices are said to be useful in adhering scrim to carpet or in manufacture of attached foamed carpet backing.
Larsen U.S. Pat. No. 4,597,817 describes processes for preparation of a water-impervious surface coating on a substrate which comprises applying to the substrate an aqueous bitumen emulsion containing, in part, 5 to 55% by weight of an acrylic prepolymer.
Ladish U.S. Pat. No. 4,544,690 discloses an aqueous rubberized coal tar emulsion composition suitable for coating and sealing bituminous substrates containing asphalt in which the coal tar emulsion includes water admixed with a small amount of carboxylated butadiene/styrene/acid copolymer latex having a particular particle size.
Keene et al. U.S. Pat. No. 4,104,211 describes pipe sealants made from an aqueous emulsion of non-cationic asphalt and rubber.
Favata U.S. Pat. No. 4,176,102 teaches sealant asphaltic emulsion compositions having 20-50 parts by volume of a copolymer prepared by copolymerization of a vinyl acetate monomer with an organic acid.
DeFatis U.S. Pat. No. 4,619,166 teaches a mortar for waterproofing and protective coverings used in building and road construction wherein the mortar includes a mixture of an acrylic emulsion and finely ground clay which has been baked at a temperature range between 600.degree. C. and 1,400.degree. C.
Jacobs U.S. Pat. No. 4,151,025 describes use of volatile organic solvent-based primers with laminated waterproofing membranes.